Allow to configure directory for remote files

[KES777]

When using wakatime plugin we can create developers time which he spent to this or that project.

Thus, when switching to different project in sublime: Project->Switch project.... We should open files from different directory to count time as ProjectX instead of ProjectY
This is done in waka time by configuring that /home/user/project/X belongs to ProjectX project and /home/user/project/Y to ProjectY

Allow to put some configurations into xxx.sublime-project configuration file so rsub will open remote files (save them temporary) under /user/home/project/X/remote directory:

 rsub:  {
     tmpdir: /user/home/project/X/remote
 }